Abstract
It briefly introduced The microcontroller function, internal structure, pin array and typical apply circuit of the MPC9239 about the MHz Low Voltage LVPECL Clock Synthesizer. The MPC9239 is taken up of some parts below. A crystal oscillator, three latches and a 12bits shift register. The LVPECL is low voltage positive emitter-coupled logic.
Key word: crystal oscillator phase-locked loop
the serial and parallel